In the related art, an instruction apparatus for directing a position in the virtual space is proposed. The instruction apparatus includes a directing device capable of being directed to a desired direction by a user in a real space toward a three-dimensional image displayed by a virtual space display means, a position and orientation detecting unit for detecting the position and the orientation of the directing device in the real space, an indicator data generating unit for generating indicator data to display, in the three-dimensional image, an indicator having a length in a direction to which the directing device is directed, and a directing device length setting unit for passing the length of the indicator to the indicator data generating unit together with the position and the orientation of the directing device in the real space (see Japanese Laid-Open Patent Publication No. 2005-50120, for example).
However, in the instruction apparatus for directing a position in the virtual space disclosed in the related art, a case may happen where the indicator is hidden by the directing device and cannot be seen from the user. That is, the instruction apparatus in the related art does not provide good operability since visibility of the indicator is not good.
The following is a reference document: [Patent Document 1] Japanese Laid-Open Patent Publication No. 2005-50120.